Efficiency and tolerance of the Vena Tech-LGM filter were assessed in
142 patients prospectively studied during a 2-6-year follow-up period.
No patients were lost to follow-up, and 137 (91.3%) scheduled control
examinations were performed. Fifty-three patients died of causes unre
lated to thromboembolic disease. Pulmonary embolism was suspected in f
ive surviving patients (3.5%). Sixteen retractions (18.4%), 16 intraca
val migrations (18.4%), and one tilt were observed. Filter patency stu
died at Doppler ultrasonography, with or without phlebocavography, gav
e the following results according to the Kaplan-Meier actuarial method
: 92% patency after 2 years of follow-up, 80% after 4 years, and 70% a
fter 6 years. Vena Tech-LGM filter obstruction was related to retracti
on (P < 10(-6)) or distal migration (P < .004). Occurrence of trophic
disease in the lower limbs during the follow-up period was related to
the initial level of deep venous thrombosis (P = .03) and had no relat
ion to the patency of the filter. The filter was effective in preventi
ng pulmonary embolism, with 70% demonstrating long-term patency, and n
o deleterious effects were imputed to obstructions observed during fol
low-up.